CakePHP使用其他数据保存属于该类的

Question

我有一个Usergroups表，什么是belongsToMany用户。

在我的控制器中

$usergroup = $this->Usergroups->get($id, ['contain' => ['Users']]);
$usergroup->users[0]->_joinData->joined = true;
if ($this->Usergroups->save($usergroup)) {
    $this->Flash->success('You have successfully joined');
}

我获得了成功的Flash消息，但我的users_usergroups表中没有为用户设置joined字段。

有什么猜测？

我在保存的实体看起来像这样。

object(App\Model\Entity\Usergroup) {

'id' => (int) 22,
'name' => 'Test',
'admin_user_id' => (int) 2,
'users' => [
    (int) 0 => object(App\Model\Entity\User) {

        'id' => (int) 2,
        'name' => 'rrd',
        'active' => true,
        '_joinData' => object(App\Model\Entity\UsersUsergroup) {

            'id' => (int) 14,
            'user_id' => (int) 2,
            'usergroup_id' => (int) 22,
            'joined' => true,
            'created' => null,
            '[new]' => false,
            '[accessible]' => [
                'id' => true,
                'user_id' => true,
                'usergroup_id' => true,
                'joined' => true
            ],
            '[dirty]' => [
                'joined' => true
            ],
            '[original]' => [
                'joined' => false
            ],
            '[virtual]' => [],
            '[errors]' => [],
            '[invalid]' => [],
            '[repository]' => 'UsersUsergroups'

        },
        '[new]' => false,
        '[accessible]' => [
            'name' => true,
            'password' => true,
            'realname' => true,
            'email' => true,
            'phone' => true,
            'active' => true,
            'responsible' => true,
            'role' => true,
            'resettoken' => true,
            'events' => true,
            'groups' => true,
            'histories' => true,
            'notifications' => true,
            'locale' => true,
            'google_contacts_refresh_token' => true,
            'last_login' => true,
            'contacts' => true,
            'usergroups' => true
        ],
        '[dirty]' => [],
        '[original]' => [],
        '[virtual]' => [],
        '[errors]' => [],
        '[invalid]' => [],
        '[repository]' => 'Users'

    },
],
'[new]' => false,
'[accessible]' => [
    'name' => true,
    'admin_user_id' => true,
    'users' => true
],
'[dirty]' => [],
'[original]' => [],
'[virtual]' => [],
'[errors]' => [],
'[invalid]' => [],
'[repository]' => 'Usergroups'
}